• Title/Summary/Keyword: Significance testing

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Do Risk-Taking, Innovativeness, and Proactivity Affect Business Performance of SMEs? A Case Study in Bangladesh

  • RAHAMAN, Md. Atikur;LUNA, Kaniz Fatema;PING, Zhao Lin;ISLAM, Mohammad Saiyedul;KARIM, Md. Mobarak
    • The Journal of Asian Finance, Economics and Business
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    • 제8권5호
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    • pp.689-695
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    • 2021
  • In the current technology-driven era, Small and medium enterprises (SMEs) have been deemed as one of the leading and prominent drivers of sustainable economic progress in emerging and developing economies such as in the Bangladesh context. Hence, it is of significance to understand what might fuel accelerating performance of SME business as increased SME performance will bring about more sustainability and strong development of SME sector within the country, through which more employment is anticipated to be generated. Therefore, the current study examines the impact of three factors: risk-taking, innovativeness, and proactiveness on SME performance in Bangladesh. The study has gathered data from SME entities in Dhaka city of Bangladesh, by applying a non-probability sampling strategy. 250 SME owners were contacted to act as respondents and finally, 180 SME owners fully completed the survey questionnaire, indicating that the final sample size is n=180. SPSS is used as a purpose of testing the hypotheses by considering a 5% significance level as acceptance criteria of the hypothesis. Hierarchical regression analysis was run to understand the impact of control variables and independent variables on SME performance and found that age of business, risk-taking, innovativeness, and proactiveness have an important impact on SME performance in Bangladesh.

Effective Sample Sizes for the Test of Mean Differences Based on Homogeneity Test

  • Heo, Sunyeong
    • 통합자연과학논문집
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    • 제12권3호
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    • pp.91-99
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    • 2019
  • Many researchers in various study fields use the two sample t-test to confirm their treatment effects. The two sample t-test is generally used for small samples, and assumes that two independent random samples are selected from normal populations, and the population variances are unknown. Researchers often conduct F-test, the test of equality of variances, before testing the treatment effects, and the test statistic or confidence interval for the two sample t-test has two formats according to whether the variances are equal or not. Researchers using the two sample t-test often want to know how large sample sizes they need to get reliable test results. This research gives some guidelines for sample sizes to them through simulation works. The simulation had run for normal populations with the different ratios of two variances for different sample sizes (${\leq}30$). The simulation results are as follows. First, if one has no idea equality of variances but he/she can assume the difference is moderate, it is safe to use sample size at least 20 in terms of the nominal level of significance. Second, the power of F-test for the equality of variances is very low when the sample sizes are small (<30) even though the ratio of two variances is equal to 2. Third, the sample sizes at least 10 for the two sample t-test are recommendable in terms of the nominal level of significance and the error limit.

Scapular spine base fracture with long outside-in superior or posterior screws with reverse shoulder arthroplasty

  • Eroglu, Osman Nuri;Husemoglu, Bugra;Basci, Onur;Ozkan, Mustafa;Havitcioglu, Hasan;Hapa, Onur
    • Clinics in Shoulder and Elbow
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    • 제24권3호
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    • pp.141-146
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    • 2021
  • Background: The purpose of the present study was to determine how long superior screws alone or in combination with posterior placement of metaglene screws protruding and penetrating into the scapular spine in reverse total shoulder arthroplasty affect the strength of the scapular spine in a fresh cadaveric scapular model. Methods: Seven fresh cadaver scapulas were allocated to the control group (short posterior and superior screws) and seven scapulars to the study group (spine base fixation with a four long screws, three with both long superior and long posterior screws). Results: The failure load was lower in the spine fixation group (long screw, 869 N vs. short screw, 1,123 N); however, this difference did not reach statistical significance (p>0.05). All outside-in long superior or superior plus posterior screws failed due to scapular spine base fracture; failures in the short screw group were due to acromion fracture. An additional posterior outside-in screw failed to significantly decrease the failure load of the acromion spine. Conclusions: The present study highlights the significance of preventing a cortical breach or an outside-in configuration when a superior or posterior screw is inserted into the scapular spine base.

The Impact of Achievement Motivation on Academic Achievement and Satisfaction of Adult Learners in an e-Learning Environment

  • HA, Young-Ja;CHUNG, Se-Jin
    • Educational Technology International
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    • 제7권1호
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    • pp.59-79
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    • 2006
  • The purpose of this study is to measure the impact of motivation on academic achievement and satisfaction of adult learners in an e-Learning environment, and to come up with strategies to improve the effectiveness of e-Learning for adult learners. In order to find answer, devices were developed, tested for validity and reliability, and use for testing variables for 289 adult learners. To measure the impact of achievement motivation on learning in job training, a multiple regression analysis was performed. The analysis results show that achievement motivation has an impact on academic achievement with significance level .001, but does not have an impact on a learner's satisfaction. Further analyses on the subcategories of achievement motivation show that individual-oriented motivation affects achievement with significance level of .001, while social-oriented motivation does not. From this finding, some strategies to boost individual-oriented motivation are suggested to enhance effectiveness of job training in e-Learning environment. Further strategies to boost individual-oriented motivation should be developed by studying various aspects of e-Learning such as learning environments, learning culture, learning modes and methods, and evaluation.

도재 축성 방법에 따른 금속 도재관의 전단결합강도 비교 (Comparison of shear bond strength according to porcelain build-up methods)

  • 이하영;조진현;이청희
    • 구강회복응용과학지
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    • 제30권2호
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    • pp.112-120
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    • 2014
  • 목적: 이 논문의 목적은 열가압법을 이용한 도재의 축성이 금속과 어떠한 결합력을 나타내는지 알아보는 것이다. 연구 재료 및 방법: 90개의 비귀금속 시편($4{\times}4{\times}8mm$)을 제작하여 세 개의 군으로 나누었다. 모든 시편은 군에 따라 2종류의 다른 방법으로 포세린 축성($4{\times}4{\times}3mm$)하였다: Group I : $Inspiration^{(R)}$, Group II : Ivoclar, IPS $Inline^{(R)}PoM$, Group III: GC Initial IQ-One $Body^{(R)}PoM$. 각 군의 시편의 반은 열순환시켰다. 모든 시편의 전단 결합 강도는 Instron universal testing machine을 이용하여 측정하였다. 통계학적 분석을 위해, 2-way ANOVA가 사용되었다. 결과: 열순환을 하지 않은 시편의 전단결합강도는 모든 실험군에서 유사한 값으로 나타나 통계적 유의성이 없었다(P > 0.05). 각 실험군에서 열순환 처리 한 시편에서는 전단결합강도의 감소가 나타났으나 통계적 유의성은 없었다(P > 0.05). 열순환 처리한 시편의 실험군간 전단결합강도 비교에서 실험 III군에서 높게 나타났으나 유의한 차이는 없었다(P > 0.05). 결론: 전단결합력의 관점에서 보았을 때 열가압성형 도재는 임상적으로 유의한 것으로 사료된다.

Increased accuracy in dictation by Korean college students when using the Korean alphabet

  • 정윤걸
    • 영어어문교육
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    • 제11권1호
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    • pp.1-15
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    • 2005
  • The purpose of this study was to investigate whether or not the use of the Korean alphabet increased the accuracy of English sentences Korean university students produced in dictation. The students were divided into three categories, beginning, intermediate, and advanced, based on the listening comprehension scores of a practice TOEIC test. The total population of 120 students were divided into two groups, control and experiment. In the first testing, the experiment group transcribed the English utterances on a practice TOEIC tape into phonological writing in Korean and then later changed the Korean writing into English words and sentences. In the second testing, the control group became the experiment group and used the Korean alphabet in transcribing the English sounds. Statistically significant differences were found in the improvement of accuracy in dictation when the Korean alphabet was used, especially for the beginning and intermediate students. By using the Korean alphabet as the phonological representation of the sounds, the students in the experiment group produced more accurate English words than the control group who went directly from the English utterances to writing in English. Statistically significant results were not produced for the advanced students. The significance of the present study relates to the need to add to the paucity of available data on the use of the Korean alphabet in teaching listening comprehension.

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The effect of zirconia surface architecturing technique on the zirconia/veneer interfacial bond strength

  • Her, Soo-Bok;Kim, Kyoung Hun;Park, Sang Eun;Park, Eun-Jin
    • The Journal of Advanced Prosthodontics
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    • 제10권4호
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    • pp.259-264
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    • 2018
  • PURPOSE. The purpose of this study was to evaluate the effect of the zirconia surface architecturing technique (ZSAT) on the bond strength between veneering porcelain and zirconia ceramic. MATERIALS AND METHODS. 20 sintered zirconia ceramic specimens were used to determine the optimal surface treatment time, and were randomly divided into 4 groups based on treatment times of 0, 1, 2, and 3 hours. After etching with a special solution, the surface was observed under scanning electron microscope, and then the porcelain was veneered for scratch testing. Sixty 3 mol% yttria-stabilized tetragonal zirconia polycrystal ceramic blocks were used for tensile strength testing; 30 of these blocks were surface treated and the rest were not. Statistical analysis was performed using ANOVA, the Tukey post-hoc test, and independent t-test, and the level of significance was set at ${\alpha}=.05$. RESULTS. The surface treatment of the zirconia using ZSAT increased the surface roughness, and tensile strength test results showed that the ZSAT group significantly increased the bond strength between zirconia and veneering porcelain compared to the untreated group (36 MPa vs. 30 MPa). Optimal etching time was determined to be 2 hours based on the scratch test results. CONCLUSION. ZSAT increases the surface roughness of zirconia, and this might contribute to the increased interfacial bond strength between zirconia and veneering porcelain.

카오스 특징 추출에 의한 용접 결함의 초음파 형상 인식 (Ultrasonic Pattern Recognition of Welding Defects Using the Chaotic Feature Extraction)

  • 이원;윤인식;이병채
    • 한국정밀공학회지
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    • 제15권6호
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    • pp.167-174
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    • 1998
  • The ultrasonic test is recognized for its significance as a non-destructive testing method to detect volume defects such as porosity and incomplete penetration which reduce strength in the weld zone. This paper illustrates the defect detection in the weld zone of ferritic carbon steel using ultrasonic wave and the evaluation of pattern recognition by chaotic feature extraction using time series signal of detected defects as data. Shown in the time series data were that the time delay was 4 and the embedding dimension was 6 which indicate the geometric dimension of the subject system and the extent of information correlation. Based on fractal dimension and lyapunov exponent in quantitative chaotic feature extraction, feature value of 2.15, 0.47 is presented for porosity and 2.24, 0.51 for incomplete penetration The precision rate of the pattern recognition is enhanced with these values on the total waveform of defect signal in the weld zone. Therefore, we think that the ultrasonic pattern recognition method of weld zone defects of ferritic carbon steel by ultrasonic-chaotic feature extraction proposed in this paper can boost precision rate further than the existing method applying only partial waveform.

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Do universal adhesives promote bonding to dentin? A systematic review and meta-analysis

  • Elkaffas, Ali. A.;Hamama, Hamdi H.H.;Mahmoud, Salah H.
    • Restorative Dentistry and Endodontics
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    • 제43권3호
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    • pp.29.1-29.13
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    • 2018
  • Objectives: The aims of this study were to conduct a systematic review of the microtensile bond strength (${\mu}TBS$) of multi-mode adhesives to dentin and to perform a meta-analysis to assess the significance of differences in the ${\mu}TBS$ of one of the most commonly used universal adhesives (Scotchbond Universal, 3M ESPE) depending on whether the etch-and-rinse or self-etch mode was used. Materials and Methods: An electronic search was performed of MEDLINE/PubMed, ScienceDirect, and EBSCOhost. Laboratory studies that evaluated the ${\mu}TBS$ of multi-mode adhesives to dentin using either the etch-and-rinse or self-etch mode were selected. A meta-analysis was conducted of the reviewed studies to quantify the differences in the ${\mu}TBS$ of Scotchbond Universal adhesive. Results: Only 10 studies fulfilled the inclusion criteria for the systematic review. Extensive variation was found in the restorative materials, testing methodologies, and failure mode in the reviewed articles. Furthermore, variation was also observed in the dimensions of the microtensile testing beams. The meta-analysis showed no statistically significant difference between the etch-and-rinse and self-etch modes for Scotchbond Universal adhesive (p > 0.05). Conclusions: Multi-mode 'universal' adhesives can achieve substantial bonding to dentin, regardless of the used modes (either etch-and-rinse or self-etch).

하모닉 영상의 물리학 (Physics of Harmonic Imaging)

  • 최민주;양정화;팽동국
    • 비파괴검사학회지
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    • 제32권5호
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    • pp.564-572
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    • 2012
  • 본 논저에서는 하모닉 영상을 소개하고, 그 원리를 및 물리적 특성을 기존 초음파 영상과 대비하여 기술한다. 인체 조직의 경계에서 반사하는 초음파 에코를 이용한 기존의 초음파 영상의 원리를 제시하고 하모닉 성분을 생성하는 비선형 초음파 전파 과정을 개념적으로 기술한다. 초음파 에코 신호로부터 하모닉 성분을 효율적으로 추출하는 pulse inversion technique를 소개하고 구현된 하모닉 영상이 종래의 초음파 영상과 비교하여 장점을 요약한다. 하모닉의 생성 기전에 따라 하모닉 영상을 분류하고 하모닉 영상을 기존의 초음파 영상과 비교한다. 하모닉 영상의 임상적 중요성, 향후 전망 및 새로운 연구 분야를 언급한다.